Signal device for tachographs



Aug. 5, 1958 A. KECK 2,846,532

SIGNAL DEVICE FOR TACHOGRAPHS Filed Jan. 25 1957 INVENTOR.

AL BERT KECK z,s4s,ss2

SiGNAlL uuvrcn non TACHOGRAPHS Albert Keck, Frankfurt am Main, Germany, assignor to Vila) Tachometer Werke, Adolph Schindliug G. tn. to. BL, Frankfurt am Main, Germany, a corporation of @ermany Application January 25, 1957, Serial No. 636,424

Claims priority, application Germany January 26, 1956 7 Claims. (Cl. 20%56) This invention pertains to warning devices. More particularly, this invention pertains to electrical devices for signalling visual or audible alarms for tachographs to which use, however, it is not restricted.

For many reasons, it is desirable to maintain vehicular speed within a certain prescribed range, and indeed, such speed limits are often prescribed by law.

As in the case of tachometers, warning signals are ineluded also in tachographs and usually consist of a lighted lamp on the instrument panel when set speeds are exceeded. The numerous known devices, however, have a common limiting feature in that they are available for only the speed setting fixed by the manufacture and are not adapted to be changed thereafter by the user.

it is an object of the invention, therefore, to provide a Warning device capable of not only being adjusted by the user to any desired speed, but also equipped with several warning signals, and yet have a simple effective means of adjusting the variant speeds at which the several signals will operate.

1 have now devised a multiple tachograph warning device which may be readily and accurately adjusted by the user for various speed requirements.

Selected limits at which the warning is to be given may now be regulated by merely turning a shaft to the desired speed indicated on the respective scales. Once the evice is set, the controls may be locked into position to prevent accidental or unauthorized tampering.

The invention achieves its variable speed warnings by adjusting the distance between the electricalcontacts relative to a graduated speed scale. Thus the device may be regulated to signal a warning Whenever a speed driven conductor riding on one contact closes a circuit by reaching the adjusted position of a second contact.

To effect the operation of this invention, a conductor is synchronized and motivated by an insulated connection with a tachograph speed writing lever and therefore movable in proportion to vehicular speed. The adjustable contact is disposed parallel to that upon which the conductor rides, but is shorter in length so that it may be set at variant relative positions thereto on a common insulated base.

The adjustable contact is provided with a rack on one portion thereof for meshing engagement with a pinion mounted upon a rotatable shaft. A scaled panel is provided at the outer end of the shaft by which the adjustment setting of the movable contact may be gauged.

Multiple signals may be attained by mounting a shaft concentrically within a hollow second shaft or sleeve which bears a second pinion for meshing engagement with a second rack on a second adjustable contact controlling a second wanting signal, etc.

The conductors here shown are of a novel spring construction adapted to bridge connection between respective sets of fixed and adjusted contacts to close the circuits of the optic or acoustic signalling devices.

The invention, therefore, provides a tachograph having multiple adjustable optic or acoustic warning signals 2,546,532 Patented Aug. 5, 1958 H employable for difierent types of vehicles with variant maximum speeds.

Further features and objects of the invention will be more readily understood from the following detail description and the accompanying drawings, in which,

Fig. 1 is a side elevation partly in section of a warning device according to my invention having two warning contacts, and

Fig. 2 is a top plan view of a warning device such as that shown in Fig. 1.

Referring now to the drawings and in particular to the embodiment of the invention illustrated in Figure 1., there is shown a warning device 10 for a tachograph and connected thereto by means of a speed writing lever 11. The electrical terminals of the device are also shown connected to an electric source such as a battery 12 to operate alarm A.

The device comprises a U-shaped block or base 15 of insulating material, to the outer face of which con tact strips or rails 14 are fixed longitudinally and centrally thereof. The fixed contact rails are connected by means of wires 16 to one of the poles of a vehicle battery 12.

Shorter contact strips or rails 15 are adapted to slide over the base 13. Here shown, the movable rails are of L-shaped right-angular formation, the longer legs of which overly the top and bottom portions of the U-shaped block 13 and are adjustably secured thereto by means of bolts 17.

As seen from Fig. 2 the movable contact rails 15 are provided with slots 18 allowing longitudinal sliding adjustment with contact bolts 17. In addition to releasably supporting contact rails 15 to the base 13, bolts 17 provide electrical connections between contact rails 15a, 51: and the second battery terminal by means of wire l9. If preferable wires 19 may be grounded.

The longer legs 15a of movable contacts 15 are provided with a rack 20 for engagement with the adjusting mechanism of the device, as will be hereinafter described.

The mechanism for adjusting the warning device consists of an inner shaft 21 concentrically mounted within an outer hollow shaft or sleeve 22 and slid-able in axial direction therewith. A pinion 23 is mounted on shaft 21 for meshing engagement with a rack 29 of movable contact 1511.

Sleeve 22 is rotatable about shaft 21, but a stop (not shown) prevents the sleeve from axial movement therewith. A pinion 24 is mounted on sleeve 22 for meshing engagement with the corresponding rack 2t) of movable contact 15b.

A disk 25 bearing a scale 26 is rigidly connected to shaft 21 for the adjustment of the upper of the two warning contacts shown in Fig. 1. A second disk 27 bearing a scale 28 is rigidly connected to sleeve 2.2 for the adjustment of movable rail 1512, the lower of the two illustrated warning contacts.

The two shafts 21 and 22 are coupled together for rotational movement by means of a pin 29 and slot 3%, a spring 33 or if preferred by friction surfaces.

The adjustment to the respective movable rails 15' may be made by means of a key (not shown) inserted into a slot 31 at the upper end of shaft 2].. A plate or panel 32 covering scale bearing disks 25, 27 may be provided and locked into place over slot 31 to avoid unauthorized tampering with the device. In circumstances where security measures are not involved, the adjustment may be easily made with a screw driver.

The covering panel 32 may be provided with apertures through which the respective scales 26, 28 on disks 25S, 27 may be read. The panel may also be provided with reference marks to aid in the adjustment of the device in setting various vehicle speed limits.

As previously stated, shafts 21 and 22. rotate together 3 under normal conditions. However, when the key is applied and pressure is brought to bear upon shaft 21, coupling 29, 3b is released whereupon shaft 21 with its scale bearing disk may be freely rotated independently of its casing 22 to effect a new setting of the adjustment mechanism.

A speed writing lever 11 connected to a tachograph is attached to double conductor springs 34a, 34-h by means of an insulating component 35. A rod 36 supported by an extension of base 13 runs through an eye 37 of the lever and provides a guide for the sliding movement of springs 34a along fixed contacts 14.

In the embodiment shown in Figure l, the device is provided with two double springs 34a, 3412 serving as contact bridges between the two contact rails 14 and 15. The inner component springs 34a are always slidably disposed on fixed rails 14, whereas the outer component springs 3412 contact the adjusted movable rails 15a, 15b. Thus the circuit is closed and the warning signal given only when the speed limits for which the device has been set are reached.

In operation, the two or more speed limits at which the warning signals are to be given are set by means of a key or like tool to adjust the position of a movable rail in accordance with the scaled speed references on the dials. When the respective adjustments have been made the covering panel 32. is locked into position over the adjustment slot 31. Conductor springs 34a always connected to one pole of a vehicle battery are slidably driven across a fixed rail 14 activated by the speed of the vehicle as transmitted by writing lever 11. No warning is given, therefore, and the device remains inoperative, until a maximum speed setting is reached, whereupon the circuit is closed by the spring conductor 34b contacting movable rail 15 in its adjusted position and operating the warning signals.

The warning device may be mounted on any suitable surface 38.

The forms of the invention here described and illustrated are presented merely as examples of how the invention may be embodied and applied. Other forms, embodiments and applications of the invention, coming within the proper scope of the appended claims, will, of course, suggest themselves to those skilled in the art.

I claim:

1. A multiple warning device for use with a tachograph to indicate attainment of predetermined speed comprising a base, a plurality of parallel fixed rails and movable rails disposed on said base, concentric shafts each provided with a pinion thereon, racks disposed on said movable rails for meshing engagement with a corresponding pinion, a key engageable with said shafts for rotation thereof in adjusting said movable rails, conductor means slidable over said fixed rails adapted to make contact with each corresponding movable rail at the adjusted positions thereof to effect respective warning signals of said device.

2. A warning device for use with tachographs according to claim 1 in which scale bearing disks are provided on said shafts to gauge the individual adjustment of said movable rails.

3. A warning device for use with tachographs according to claim 2 in which said shafts are provided with a spring coupling, concentric slots and a pin engaging said slots to maintain said shafts in adjusted rotatable relationship.

4. A warning device for use with tachographs according to claim 3 wherein pressure effected by said key disengages said coupling for readjustment of said shafts and said movable rails.

5. In a tachograph including a speed writing lever movable over a speed graduated surface, a speed warning device comprising an insulated base, a fixed contact rail disposed on said base defining said surface, an adjustable contact rail disposed on said base in parallel spaced relation to said fixed rail, a rack provided on said adjustable rail, a spring conductor bridge driven by said speed-writing lever, said bridge adapted to ride on said fixed rail and project into the path of said adjustable rail whereby a closed electrical circuit for actuating said device may e established, and a pinion engaging said rack to regulate the position of said adjustable rail at a selected speed at which said device is to be actuated.

6. A warning device according to claim 5 wherein said fixed contact is of greater length than said adjustable contact and disposed along the full length of said base.

7. A warning device according to claim 5 wherein said condutcor bridge is insulatedly mounted on said lever.

References Cited in the file of this patent UNITED STATES PATENTS 2,780,686 Elliott Feb. 5, 1957 

